1. Field of the Invention
The present invention relates to a spring manufacturing apparatus and, more particularly, to a spring manufacturing apparatus for continuously feeding a wire to be formed into a compression spring or a tension spring, winding the wire into a predetermined coil diameter by pressing a point tool against the wire, and growing a coil having a predetermined pitch by winding the wire using a pitch tool, thereby forming a coil spring with a desired shape.
2. Description of the Related Art
[Twin pin right hand wind]
For example, as shown in FIG. 31, a spring manufacturing apparatus for forming a right hand coil by using two point tools has a forming table 102 parallel to the direction in which a wire is fed. On this forming table 102, feed rollers 110 for feeding a wire W, a mandrel 103 for applying shearing force to the wire in cooperation with a cutting tool (not shown) during cutting, and two point tool assemblies 116 and 126 are arranged. These two point tool assemblies 116 and 126 are radially arranged around an output portion O2 of the wire W from the feed rollers 110. The vertical position of the mandrel 103 on the forming table can be properly changed in accordance with the coil diameter. The mandrel 103 is arranged above a straight line along the feed direction of the wire W, and the distance from the output portion O2 of the wire W is set in accordance with a desired coil diameter.
The point tool assembly 116 is attached to a tool driving shaft R1 which is above the output portion O2 off to the right at an angle of 45.degree.. The point tool assembly 116 has rails 111 fixed on the forming table, a slider 112 slidably disposed on the rails 111, and a driven shaft 113 which is disposed at one end of the slider 111 and abuts against a cam (not shown) pivotally, axially supported by the tool driving shaft R1. A tool fixing arm 114 is fixed to the slider 112, and a point tool T1 is fixed to the end portion of the tool fixing arm 114. This point tool T1 can be finely adjusted by a micrometer 115.
The point tool assembly 126 is attached to a tool driving shaft R2. The axial center of this tool driving shaft R2 is on a straight line L1 which passes through the output portion O2 and extends along the feed direction of the wire W. The tool driving shaft R2 is disposed to the right of the output portion O2. The point tool assembly 126 has components identical to those of the point tool assembly 116. Therefore, the same reference numerals denote the same components, and a detailed description thereof will be omitted. A tool fixing arm 124 is fixed to a slider 112, and a point tool T2 is fixed to the end portion of the tool fixing arm 124. This point tool T2 can be finely adjusted by a micrometer 125.
The tool fixing arms 114 and 124 are so constituted that the point tools T1 andT2 form an angle of 90.degree. around a desired coil diameter.
[Twin pin left hand wind]
To form a left hand coil by using two point tools, as shown in FIG. 32, two point tool assemblies 136 and 146 are radially arranged around an output portion O2 of a wire W from feed rollers 110 on a forming table 102. A mandrel 103 is arranged below a straight line along the feed direction of the wire W, and the distance from the output portion O2 of the wire W is set in accordance with a desired coil diameter. Note that the same reference numerals as in the point tool assembly 116 explained in FIG. 31 denote the same parts in FIG. 32, and a detailed description thereof will be omitted.
The point tool assembly 136 is attached to a tool driving shaft R2. The axial center of this tool driving shaft R2 is on a straight line L1 which passes through the output portion O2 and extends along the feed direction of the wire W. The tool driving shaft R2 is disposed to the right of the output portion O2. A tool fixing arm 134 is fixed to a slider 112, and a point tool T1 is fixed to the end portion of the tool fixing arm 134. This point tool T1 can be finely adjusted by a micrometer 135.
The point tool assembly 146 is assembled to a tool driving shaft R3 which is below the output portion O2 off to the right at an angle of 45.degree.. A tool fixing arm 144 is fixed to a slider 112, and a point tool T2 is fixed to the end portion of the tool fixing arm 144. This point tool T2 can be finely adjusted by a micrometer 145.
The tool fixing arms 134 and 144 are so constituted that the point tools T1 and T2 form an angle of 90.degree. around a desired coil diameter.
[Single pin right hand wind]
To form a right hand coil by using one point tool, as shown in FIG. 33, one point tool assembly 156 is radially arranged around an output portion O2 of a wire W from feed rollers 110 on a forming table 102. A mandrel 103 is arranged above a straight line along the feed direction of the wire W, and the distance from the output portion O2 of the wire W is set in accordance with a desired coil diameter. Note that the same reference numerals as in the point tool assembly 116 explained in FIG. 31 denote the same parts in FIG. 33, and a detailed description thereof will be omitted.
The point tool assembly 156 is attached to a tool driving shaft R2. The axial center of this tool driving shaft R2 is on a straight line L1 which passes through the output portion O2 and extends along the feed direction of the wire W. The tool driving shaft R2 is disposed to the right of the output portion O2. A tool fixing arm 154 is fixed to a slider 112, and a point tool T1 is fixed to the end portion of the tool fixing arm 134. This point tool T1 can be finely adjusted by a micrometer 155.
The tool fixing arm 154 is so constituted that the point tool T1 is parallel to the straight line L1 which passes through the center of a desired coil diameter and extends along the feed direction of the wire W.
[Single pin left hand wind]
To form a left hand coil by using one point tool, as shown in FIG. 34, one point tool assembly 166 is radially arranged around an output portion O2 of a wire W from feed rollers 110 on a forming table 102. A mandrel 103 is arranged above a straight line along the feed direction of the wire W, and the distance from the output portion O2 of the wire W is set in accordance with a desired coil diameter. Note that the same reference numerals as in the point tool assembly 116 explained in FIG. 31 denote the same parts in FIG. 34, and a detailed description thereof will be omitted.
The point tool assembly 166 is attached to a tool driving shaft R3 which is off to the lower right of the output portion O2. A tool fixing arm 164 is fixed to a slider 112, and a point tool T1 is fixed to the end portion of the tool fixing arm 164. This point tool T1 can be finely adjusted by a micrometer 165.
The tool fixing arm 164 is so constituted that the point tool T1 is parallel to a straight line L1 which passes through the center of a desired coil diameter and extends along the feed direction of the wire W.
In the conventional spring manufacturing apparatus as described above, the point tools are slidably disposed to abut against a wire being fed and define the coil diameter of a spring. On the forming table, the arrangement of the point tools can be appropriately changed in accordance with a desired spring shape. The forming table defines thespring formation space in the apparatus main body.
Also, Japanese Patent Publication No. 2553406 has disclosed a coiling apparatus including a link mechanism which links two coiling pins.
In the above spring manufacturing apparatus, however, when the wind direction, the coil diameter, or the like of a coil is to be changed, it is necessary to readjust the relative positional relationship by removing the mandrel and the point tool assemblies from the forming table, while the tip shape of a tool is changed where necessary.
In the coiling apparatus disclosed in Japanese Patent Publication No. 2553406, on the other hand, to change the wind direction of a coil it is necessary to manually change the position of the link mechanism although the positions of slide members for sliding the two coiling pins need not be changed.
These efforts require much labor and time of workers, and skill is necessary to accurately set the tool positions.